We assessed the presence of neutralizing antibodies for hepatitis C virus (HCV) in an experimental intravenous immune globulin (IGIV) preparation enriched in antibodies to HCV in chimpanzees. An H inoculum standardized for low infectious doses was provided by Dr. Purcell of NIH. A experimental chimpanzee received a diluted H inoculum pre-incubated with the experimental IGIV having high levels of antibodies to HCV envelope proteins (E1 and E2). A control chimpanzee received the same H inoculum pre-incubated with a commercial IGIV prepared from screened plasma and devoid of both anti-El and anti-E2. Both IGIVs were solvent/detergent treated. Another control chimpanzee received the same H inoculum pre- incubated with a 5% solution of Albumin (Human). Thus far (after 7 months of inoculation), both control chimpanzees have shown positive seromarkers indicating HCV infection whereas the experimental chimpanzee has not. HCV RNA testing of serum specimens is in progress. The lack of infectivity in the experimental chimpanzee would indicate the presence of neutralizing antibodies for HCV in the experimental IGIV enriched with anti-El and anti-E2. We began to determine anti-hepatitis A virus (anti-HAV) levels in lots of Immune Globulin (Human) (10) utilizing an EIA kit and an WHO/CBER Standard. Preliminary results indicate that anti-HAV levels in recent 10 lots were lower than those manufactured before 1990. We also have established procedures to determine the products' purity by capillary zone electrophoresis.
